Despite seeming like a bystander, your baby is attuned to your social life (assuming you have one, which, with a baby, would be amazing). Every time you interact with someone, your wee babe is watching, eagerly slurping up social conventions.

Babies are pretty good at figuring out who they want to interact with. The answer in most cases: Nice people. And that makes sense. The helpless wailers need someone reliable around to feed, change and entertain them. So to find out how good babies are at reading other people’s social relationships, University of Chicago psychologists showed 64 9-month-old babies a video of two women eating. Sometimes the women ate from the same bowl and agreed that the food was delicious, or agreed that it was gross. Sometimes the women disagreed.

Later, the women interacted again, either warmly greeting each other and smiling, or giving each other the cold shoulder, arms crossed with a “hmph.” Researchers then timed how long the babies spent looking at this last scene, with the idea that the longer the baby spent looking, the more surprising the scene was.

Eating is an inherently social event in most people’s lives, and particularly for babies. If the women shared an opinion about the food — either good or bad — they would be more likely to be friends, the rationale went. Would babies buy into this and also expect two people with similar culinary opinions to be friends?

Yes, it turns out. Babies spent a long time looking when the women agreed on food but later gave each other the cold shoulder. “How could these women, who together enjoyed the mysterious contents of that green bowl, be so cruel to one another moments later?” the babies wondered. (In case it’s not obvious, that’s a wildly speculative guess at pre-verbal infants’ inner monologues.) The same held true for when the women disagreed on the food but then acted like BFFs.

The results suggest that long before they have any friends themselves, young babies are already making predictions about how people get along. And that’s a social skill that can’t come too early.